The industry's most anxiously awaited quad-core processor has been curiously missing in action. Because it brings the scrappy chipmaker's hot new 10h architecture to the desktop, and because it's the scrappy chipmaker's first desktop quad, the chip was shaping up as something of an Intel killer when it was first discussed a few months ago.Then it faded into the background when AMD launched its Barcelona quad-core server processor in September.

AMD continued to promise that Phenom would appear before the end of the year. But Phenom dropped further down on the radar screen amid scattered but persistent reports of early shortages of its sister Barcelona processor. When I spoke with an AMD spokesman last month, he denied that there were any such shortages, and indeed it seems like the situation was more in the nature of a normal manufacturing ramp-up than any sort of real problem.

With Phenom, though, we've got a different dynamic at play. This chip is so important to AMD's desktop future that the company is in something of a quandry. AMD has promised to ship Phenom by the end of the year. At the same time, it's widely accepted (and AMD has not denied) that Phenom won't be available in appreciable quantities until early next year.

Thus, it seems like the announcement that Phenom is shipping is being pushed back as late as possible. That way, there will be less of a lag between that announcement, with not that many Phenoms around for enthusiasts (i.e., I'm talking about users, not OEMs) to get their hands on, and broader availability in 2008

Now, there's widespread speculation that AMD will formally launch Phenom next week.

Whether that's true or not, I do know that the Phenom line-up has come to light, because Directron.com is taking preorders for three Phenom chips. So here's what we can expect:

Phenom X4 9500. A 2.2-GHz clock, 4MB cache, 95W. Priced at $286.

AMD's Phenom desktop quad-core processors are available at Directron.com. (Click picture to enlarge.)

P.S. The success of the Phenom family is all the more important for AMD, given the momentum Intel has gained with its announcement this week of its 45-nm Penryn processors.